High-frequency apparatus



April 5, 1949. F. SORG HIGH-FREQUENCY APPARATUS 4 Sheets-Sheet 1 Filed May 2, 1945 INVENTOR LLOYD F 50/?6 BY MJM ATTORNEY April 5, 1949. 1 F. SORG 6,05

HIGH-FREQUENCY APPARATUS Filed May 2, 1945 4 Sheets-Sheet 2 INVENTOR LLOYD F 5026 ATTORNEY April 5, 1949. 1.. F. SORG HIGH-FREQUENCY APPARATUS 4 Sheets-Sheet 5 Filed May 2, 1945 l l'l l l l INVENTOR ZLL LOYD F 5026 ATTORNEY 0 6 m a? w M 7 7 I 4% ll fl U 9 Q U M n; 4 WV 8 7 0 f5 6 8 7 April 5, 1949. so I 2,466,058

HIGH-FREQUENCY APPARATUS Filed May 2, 1945 4 Sheets-Sheet 4 INVENTOR v0 F SORG L4. Y gy ATTORNEY Patented Apr. 5, 1949 UNITED STATES ATENT OFFICE HIGH-FREQUENCY APPARATUS Lloyd F. Sorg, Garden City, N. Y., assignor to The Sperry Corporation, a corporation of Delaware 21 Claims. 1

This invention relates to mechanism for tuning electron discharge apparatus and is particularly concerned with tuning mechanism for reliably and accurately controlling electrode spacing in electron discharge apparatus.

The invention concerns mainly mechanism for obtaining and maintaining parallel association and relative displacement of electrodes in electron discharge apparatus of the type wherein an electron beam is coupled in energy exchanging relation with one or more oscillating ultra high frequency fields. In its preferred embodiment about to be disclosed, the invention will be described as applied to control of electrode spacing in ultra high frequency electron discharge apparatus of the kind usually characterized as usually electron velocity modulation apparatus.

As disclosed in United States Letters Patent to Varian No. 2,242,275, the output frequency of electron velocity modulation apparatus may be controlled by variation of the spacing of electrodes between which are disposed portions of the ultra high frequency field or fields traversed by an electron beam. This is true whether the electrodes comprise grids or other elements interposed in the path of the electron beam, or are apertured to surround the electron beam, or are otherwise arranged between the electron beam and associated field.

United States Letters Patent No. 2,250,511 discloses an electron discharge device of the type to which the preferred embodiment of the invention is applied. This device comprises an alternating ultra high frequency field coupled by a pair of spaced electrodes to a unidirectional current electron beam which passes from a suitable cathode or other source through the field portion between the electrodes toward a negative reflecting electrode. The latter returns the beam back through the field portion between the pair of spaced electrodes. In each traverse of the pair of spaced electrodes, the electron beam exchanges energy with the field. During the first passage of the electron beam through the field, the alternating field imparts energy to the beam. According to accepted theories of electron velocity modulation, the electrons travelling between the electrodes are speeded up or slowed according to the instantaneous direction of the field acting thereon and such tends to create electron grouping in the beam as the faster moving electrons overtake the slower, the instantaneous grouping being a function of the frequency of the ultra high frequency field producing it.

As the electron beam is repulsed by the more negative reflector electrode which reverses the beam in direction but does not change it in any other characteristics according to accepted theories, the electron beam returns through the portion of the field between the spaced pair of electrodes and is thereby coupled to the field in such relation thereto that the field extracts ultra high frequency energy therefrom by a process which is the reverse of that obtaining during the first passage. This is accomplished because the transit time of the electrons on the reflector electrode side of their coupling with the field is chosen such as to permit optimum grouping of the electrons in the beam and the association of such grouping in proper phase with alternation of the field between the electrodes during the return passage to deliver more energy to the field than is extracted therefrom. This theory of velocity modulation which has been widely accepted is explained fully in said Patents No. 2,242,275 and No. 2,250,511 to which reference is made for further detail, but it will be understood that the mechanism of the invention is independent of such theory of operation.

Experience has indicated that probably the most reliable practical way of varying and controlling frequency in the above described apparatus is to vary the electrode spacing thereby varying the characteristics of the field between the spaced electrodes and consequently the character and degree of coupling between the electron beam and the field. It has further been ascertained that parallel association of the electrodes is preferable as obtaining optimum coupling between the electron beam and field and that maintenance of parallelism between these electrodes as they are displaced to vary the frequency is an optimum mechanical and electrical condition.

For that reason various attempts have previously been made to provide tuning mechanism for obtaining parallel displacement of such electrodes but to my knowledge none of these mechanisms are in commercial use probably because of mechanical complexity and non-uniform operation. My invention provides a reliable and accurate tuning mechanism for parallelly relatively displacing electrodes such as above characterized. Since such mechanism may be provided for adaptation to existing electron discharge devices as Well as originally built with the device, the invention is such as to embrace the tuning mechanism both separately and in combination with the electron discharge device as will appear in the claims.

With the above in mind, it is a major object of the present invention to provide a novel tuning mechanism for accurately and reliably obtaining parallel association and relative displacement of spaced electrodes adapted to be coupled to an electron beam in electron discharge ap aratus.

A further object of the invention is to provide an electron discharge device having spaced parallel electrodes in energy exchanging association with an electron beam and including novel tuning mechanism for controlling parallel relative displacement of the electrodes.

A further object of the invention is to provide a novel multiple lever tuning mechanism interposed between spaced electron permeable sections of an ultra high frequency discharge device and adjustable for effecting accurately parallel movement of said electron permeable sections toward or away from each other. a

A further object of the invention is to provide a novel ultra high frequency tuning mechanism for regulating the spacing of two parallel electron permeable electrodes wherein movement of an adjustable control member transverse to the desired direction of relative movemnt of said electrodes is converted to parallel movement of said electrodes toward or away from each other.

Further objects of the invention will presently appear as the description proceeds in connection with the appended claims and the annexed drawings wherein:

Figure 1 is a side elevation of an electron discharge device illustrating especially certain details of a parallel motion tuning mechanism according to the present invention;

Figure 2 is a side elevation similar to Figure 1 but mainly in section illustrating more details of the tuning mechanism;

Figure 3 is a top plan view, partly in section substantially along line 33 of Figure 2, of the device of Figures 1 and 2, illustrating further details of the electrode spacing adjustment linkage of the tuning mechanism of Figure 1;

Figure 4 is a, fragmentary top plan view partly in section on line 44 of Figure 2 illustrating especially the mounting plate for the tuning mechanism;

Figure 5 is a substantially isometric view of the movable linkage of the tuning mechanism of the device of Figures 1-4;

Figure 6 is a side elevation of an electron discharge device of different structure provided with a parallel motion tuning mechanism also of different structure according to a further embodiment of the invention;

Figure '7 is an elevation of the device of Figure 6 looking at it from a position about ninety degrees displaced from Figure 6;

Figure 8 is a fragmentary top plan view partly in section of certain elements of the parallel motion tuning mechanism of Figures 6 and 7;

Figure 9 is a side elevation mainly in section of an electron discharge device similar to that of Figure 1 provided with tuning mechanism according to a further embodiment of the invention; and

Figure 10 is a section taken substantially along line Ill-I 0 of Fig re 9.

Referring particularly to Figures 1 through 5, inclusive, the illustrated embodiment of the inventionincludes an electron discharge device II having a pronged base I2 sealed to a lower envelope portion I3 which is preferably a metal stamping having fixed thereto a transverse platform in the form of a relatively heavy rigid annular'metal plate I4. Arranged in spaced parallelism with plate I4 is a second relatively heavy rigid annular metal plate I5 which, as illustrated in Figure 2, is affixed to a cup-shaped metal stamping comprising a substantially rigid cylindrical shell of a cavity resonator I6 adapted to contain an ultra high frequency field as will appear.

A pair of parallel grids I1 and I8, preferably but not necessarily of the type shown in Figure 3 at 22, are mounted respectively centrally of the upper rigid end Wall of resonator shell I6 and on the adjacent end of a tubular stamping I9 disposed coaxially of envelope portion I3 and aflixed rigidly thereto as by silver soldering. Grids I1 and I8 are disposed in the path of an electron beam emitted from a cathode 2| and passed through an accelerating grid or like electrode 22 fixed upon stamping I3 in coaxial alignment with the beam and grids I1 and I8. Grids I'I, I8 and 22 are parallel. Above grid I1 and coaxial with the resonator is mounted a metallic cup-shaped electrode 23 which is rigidly mounted and insulated electrically from the walls of shell I6 in an envelope portion 24 above the shell. Electrode 23 is conductively connected to a metallic terminal cap 25 by which a negative potential may 'be applied thereto during operation.

Resonator I6 is preferably a relatively shallow hollow cup-shaped metallic shell of cylindrical transverse section having its lower end wall opposite grid I'I closed by an annular flexible diaphragm 26 of beryllium copper or suitable highly flexible and fatigue resistant material which has its outer periphery rigid with the cylindrical side wall of shell I6 and its inner periphery rigid with stamping I9. By this construction it will be apparent that the grids I1 and I8 are flexibly and resiliently inter-connected by flexible and resilient wall 26 of resonator Hi. This connection permits the spacing of grids I1 and I8 to be selectively varied, and below will be described mechanism for accurately maintaining and varying the relative parallel spacing of grids I1 and I8 for controlling the output frequency of resonator As clearly illustrated in Figure 2, grids I1 and I8 are rigid with parallel plates I4 and I5, respectively, so that parallel relative displacement of these plates toward and away from each other will automatically result in similar parallel relative displacement of grids I1 and I8. According to the invention I provide parallel motion producing mechanism interposed between plates I4 and I5, such parallel motion being permitted and controlled in part by the resilient nature of deformable wall 26 of resonator shell I6.

In addition to deformable Wall 26 and shell I6, plates I4 and I5 are interconnected by a series of equally circumferentially spaced tension springs 29, preferably three in number, andthe cooperating parallel motion producing mechanism to be described.

Parallel motion producing mechanism threaded vide a pivot about which lever 35 may rockon an axis. disposed generally perpendicular to the desired direction of relative movement of grids I! and I8 and the direction of the electron beam from cathode 2!.

As illustrated best in Figure 5, the lower horizontal leg 34 of tuning, lever 35 is bifurcated and is provided at both terminals with upwardly and outwardly bent portions providing tabs 31 and 38 disposed at a common higher level than the remainder of leg 34. Depending from tabs 31 andv 38 are hard, preferably spherical-ended, bearing elements 39 and 4| rigid with leg 34 and adapted to bear on the upper fiat surfaces of adjacent ends of an oppositely facing generally U-shaped yoke lever member 42.

Yoke lever 62 is rockably supported at two spaced points. by upstanding bearing pivot members 43 and 44 which, as illustrated in Figure 4, may be rigid with or integral parts of mounting plate 35. Bearing members 43 and 44. have hard bearing terminals. 45 and 45, respectively, which are preferably spherical and adapted to seat with similarly shaped sockets A5 and 45' formed in the bottom surface of yoke 42.

The upper surface of yoke 42 is formed with shallow, preferably spherical, bearing recesses 4! and 48 for the seating of the similarly shaped hard lower ends of struts 49 and 55, which are threaded in plate l5 for the purpose of initially adjustinng and maintaining the spacing of plates l4 and I5 in cooperation with the action of springs 29. There are three of these struts, the third strut 5| having its lower hard spherical end bearing in a similarly shaped recess 52 formed in the upper surface of leg 34 of tuning lever 35 as indicated in Figure 5.

Struts 49, 513 and 5| may simply be ordinary threaded bolt-like elements rotatably threaded in plate l5 and bearing on the yoke and tuning lever, respectively, but are illustrated as being of a special compound thermal compensation type which prevents ambient temperatures from altering the frequency of resonator I5. However, the present invention contemplates the use of any equivalent mechanical adjustment between plates [4 and I5 and is not limited to the illustrated thermal compensating types of struts but may embody any suitable struts or devices having equivalent function. Struts 43, 50 and- BI are preferably equally spaced circumferentially and equidistant between springs 29.

In operation, it will be obvious that tuning lever 35 is supported for transverse pivotal movement about pivot 33 and rocks thereon in a path in which is non-parallel with the desired relative displacement motion of grids i! and I3 produced by such pivotal movement. Springs 29 and struts 49 through 5! act in opposition to each other. Springs 29 are of such heavy value that they follow all strut adjustments and take up any mechanical play occasioned by looseness in the struts. As lever 35 rocks clockwise about pivot 35 in Figures 1 and. 2, it will be seen that this will lower that portion of lever 35, which is on the right side of pivot 36 in Figure 2 and which contacts strut 5!, thereby permitting tension springs 29 to pull plates l4 and 15 toward each other at this point. Simultaneously and similarly the portion of. the tuning lever comprising tabs 37 and 38 is raised-,.thereby permitting springs 29 acting through struts 49 and 50 to rock yoke 42 counterclockwise about pivots. 45 and 46 and pull plates I4. and I5 toward each other at these points. The combined action of springs 29, yoke 42 and tuning lever is such that when lever 35 is rocked clockwise in Figure 2, the spacing of parallel plates l4 and I5, is varied parallelly and, since grids I! and. I8 are parallel to those plates desired parallel displacement of grids H and 18 toward each other is obtained.

When tuning lever 35 is rocked in a counterclockwise direction in Figure 2 about pivot 36, it raises the portion of leg 34 on the right side of pivot 36 thereby raising strut 5| against the force of springs 29 and tending to separatethe plates 14 and ['5 at this point. The tabs 3'! and 3B are simultaneously caused to bear down on yoke 42 and rock yoke 42 clockwise about its pivots 4-5 and 46 to cause simultaneous upward displacement of struts 49' and 50 against the opposition of springs 29. Thus when lever 35 is rocked counterclockwise uniform parallel separational displacement of plates l4 and I5 and consequently grids l1 and I8 is thereby efiected. Grids ii and I8 follow faithfully the relative movements of plates Id and I 5, so the above described adjustment affects parallel relative displacement of grids l1 and H3 in both directions.

It is known that variation in spacing of resonator grids provides variation of the character of the field within the resonator and so changes the frequency characteristics of the resonator that the output frequency extracted on coaxial terminal 53 may be accurately and reliably variably regulated by control of the position of tuning lever 35. g

The structure of resonator I5 is preferably similar to that illustrated in United States Letters Patent No. 2,345,642 to which reference is hereby made for further detail as to such stru ture or explanation of the effect of variation of grid spacing on the resonator frequency.

Mic'i'ometer mechanism for adjusting tuning lever The Vernier micrometer mechanism to be described hereinafter, Which may be used to regulate the tuning lever to produce parallel motion tuning, is described and claimed in a divisional application Serial No. 702,871, filed October 11, 1946.

As illustrated in Figures 1 and 2, the electron discharge device of the invention is preferably mounted upon an instrument panel P by means of a relatively heavy bracket 54' having an upright leg 55 secured rigidly to the panel as will be described, and a lower horizontal leg 55 secured rigidly to plate 14 as by extension of screws 3|.

Referring now to Figures 2 and 3, a threaded trimming shaft 51 is mounted for rotation within an internally and externally threaded tuning shaft 58 which has secured thereto as by set screws 59 an outer cylindrical drum 6| by which it may be manually rotated. Shaft 58 in turn is rotatably threaded and supported in an internally threaded bushing 52. Bushing 62 has an enlarged head 63 seated in a suitable recess in bracket leg 55 and extends through an enlarged opening in panel P. Bushing 62 is also externally threaded to receive a lock nut and washer assembly 64 which when tightened secures both bushing, 52 and bracket 54 to the panel. Shaft 58 carries a longitudinally extending spring finger 65 adapted to fit with a notch 65 in a bushing, extension member Bl which surrounds shaft 52 and is internally threaded upon bushing 52.

Bushing extension 67 has secured thereto, as by nut 68,, the inner drum 69 of the. micrometer sothat. drum 69- is stationary withbushing ex- -tension 61.

Trimmer shaft 51 has at its outer end an enlarged manual knob H and at its inner end a rounded bearing tip 12 adapted to engage the upright leg of tuning lever 35. A snap ring 13 is mounted in a suitable annular recess at the end of trimmer shaft 51 and. may abut the adjacent end of tuning shaft 58 to limit relative axial movement of the two shafts.

In operation, it will be seen that when outer drum BI is rotated it positively rotates tuning shaft 58 within bushing 62. When drum 6| is rotated to advance shaft 58 to the left in Figure 2, the engagement of the end of shaft 58 with snap ring 13 insures that trimmer shaft end 12 advances to the left thereby rocking tuning lever 35 counterclockwise and causing parallel separation of grids l1 and I8 and securing frequency regulation of the resonator. Each time drum 6| has turned a complete revolution about its axis, the bent end of spring '65 drops into notch 66 and this can be felt by the fingers of the operator during manipulation of drum 6|. This notch indicates to the operator that he is in the center of a wave band, fine frequency adjustment within that band being obtainable by rotation of trimming shaft 51. Drum 6| is in effect a coarse adjustment of frequency and each complete revolution of drum 6! effects a displacement of outer drum 8! an axial distance of one scale division 14 on inner drum 69 as indicated in Figure 3. When drum BI is oppositely rotated, shaft end 12 is withdrawn from lever 35 which follows it under the urge of springs 29, and reverse control of the resonator frequency is accomplished.

Fine adjustment of tuning lever 95 is accomplished by rotating knob H. This is done when spring 65 is disposed in recess 66, denoting the middle of a wave band, and provides sufficient holding force to insure that rotation of trimming shaft 51 within tuning shaft 58 does not cause rotation of tuning shaft 58. The threads of trimmer shaft 51 are very fine as compared to those of shaft 58, preferably being of the double lead variety, and rocking movement of tuning level 35 is controlled by this fine adjustment.

I have thus provided both a coarse and fine adjustment for controlling pivotal movement of tuning lever 35, and this adjustment, coupled with the mechanism by which parellel relative spacial displacement of grids l1 and i8 is assured when lever 35 is rocked, provides a reliable and accurate frequency control which is not available in other mechanisms for tuning cavity resonators to my knowledge.

I have found that the above described parallel motion tuning mechanism provides for an optimum tuning range within the limits of the diaphragm 28, and that the tuning adjustment made available thereby is more even and reliable than can be obtained in prior tuning mechanisms heretofore employed in such devices.

In use of the apparatus, original parallelism between plates 54 and I is obtained by pre-adjustment of struts 49, 59 and 5| and this adjustment is locked and remains undisturbed during normal use of the apparatus. Once this initial parallel relation of plates l4 and I5 is set, rocking movement of the tuning lever will insure parallel relative displacement of the grids throughout the entire tuning range permitted by fiexure of diaphragm 26.

Figures 6-8 illustrate the invention in another, although similar, embodiment as applied to an electron discharge device of a different typefrom that of Figures 1 through 5 and having a simpler type of micrometer adjustment for the tuning lever.

Referring to Figure 6, spaced rigid annular plates 15 and 16 are rigid with parallel grids mounted coaxial with an electron beam passing between opposite and flexibly connected end walls of a cavity resonator 11 which may be the same as resonator l6 of Figure 2. It will be understood that relative parallel movement of plates 15 and 16 will accomplish similar parallel movement of the resonator grids just as in Figures 1 through 5. Plates 15 and 16 are connected by two diametrally opposite posts 18, each of which is rigidly secured to lower plate 15 and passes freely through a suitable aperture in upper plate 16, a compression spring 19 being provided about each post between the enlarged upper end of the post and upper plate 16. Springs 19 constantly urge the plates 15 and 16 toward each other.

The whole electron discharge device is mounted on panel P by a bracket 89 having a horizontal leg secured to lower plate 15 as by screws 8! and an upright leg secured to panel P as by screws 82.

A tuning lever 83 has a generally horizontal bifurcated leg 84 supported upon two spaced pivots 85 and 86 rigid with plate 15. The upwardly displaced terminals of leg 84 are provided with depending hardened rounded bearing portions 81 and 88 adapted to seat in suitably formed recesses in the upper surface of a yoke lever 89 which in turn is rockably mounted upon spaced supporting pivots 9| and 92 upstanding from plate 15. One of the bearing portions on the end of leg 84, such as at 88, may be the endof a screw held in locked adjustment as by a nut 93. The purpose of this adjustment is to correlate leg 84 with yoke 89 to insure proper bearing contact and relative parallelism of the two in the assembly.

A series of three adjustable struts 94, and 96 are provided for maintaining spacing between plates I5 and 16 in cooperation with springs I9. Struts 94 and 95 bear on the upper side of leg 84 of the tuning lever, and strut 96 bears on the upper side of yoke 89, and all three struts are threadedly mounted in plate 16 so that they may be adjusted to obtain initial parallelism of plates 15 and 16 and locked to preserve that adjustment and relation.

As illustrated in Figure 6, a micrometer adjustment device is mounted on the panel and comprises a threaded shaft 91 rotatably threadedly mounted in an internally threaded bushing member 98. The outer end of shaft 91 carries a manual operating knob 99 and an outer barrel H. An inner barrel N32 is fixedly mounted on the panel as by a lock nut I03 and washer I04. The inner barrel contains surface graduations and rotation of the outer barrel may be indexed with those graduations for indicating frequency adjustment. Rotation of knob 99 in either direction will effect either clockwise or counterclockwise rocking of tuning lever 83 and operation of this embodiment of the invention is so similar to that of the embodiment of the invention described in Figures 1 through 5 that further detail is felt to be unnecessary. In both devices spacial displacement of parallel plates to which the parallel grids are fixed is effected by rotation of transversely disposed threaded elements.

The adjustment at 93 at one side of the bi furcated tuning lever leg 84 enables the parts to be made with relatively large tolerances so that, in spite of the accuracy which may be obtained by means of the adjustment once the parts are properly in assembled position, the accuracy required for manufacture of the parts is relatively small and the tuning mechanism is relatively inexpensive to manufacture.

A further embodiment of the invention is illustrated in Figures 9 and 10 wherein an electron discharge device II similar to that of Figure 1 is provided with coarse and fine tuning mechanism. Similar parts are indicated by lik reference characters.

A semi-circular transverse yoke I05, similarly to yoke 42 in Figure 1, is pivotally mounted on the spaced bearing pivot members 43, 44. Struts I06 and I01 are interposed. between yoke I05 and plate I5, screws I08 being rotatably threaded in plate I5 and locked by nuts I09 to provide for factory tuning adjustment. The opposite ends of struts I06 and II are preferably ball-ended and seated in cooperating sockets in yoke I and screws I08.

Mounting plate 30 is provided in this embodiment with a second pair of bearing pivot members I I0 and III similar to those at 43, 44 on which is seated the transverse leg II2 of a tunning lever H3. Leg II2 comprises a semi-circular bifurcated portion terminating in upbent tabs I I4 and I I 5 provided with adjustable pivot members H0 and Ill adapted to bear on the upper surfaces of the corresponding ends of yoke I05.

Tuning lever 1 I3 is formed at its upper end with a fiat straight portion 'I I8 adapted to be engaged by the inner end of a tuning adjustment shaft I I9 rotatably threaded in a bracket I 20. Bracket I20 is preferably fixed to a stationary panel or the like and is secured to device II as by screws 3|. Shaft H9 is formed with a knurled knob I2I for manual manipulation.

Leg H2 of tuning lever H3 is provided with a bearing pivot member I22 on which is universally pivoted the lower end of a trimmer level I23 having a flat upper portion I24 adapted to be engaged by a trimmer shaft I 25 rotatably threaded concentrically within tuning shaft H9 and having its inner end projecting freely through an aperture I28 in lever I I3. A knurled operating knob I2! is provided on the other end of shaft I25 beyond knob I2 I A third strut I28, shorter than the other two struts and parallel thereto, extends between a socket in the upper surface of trimmer lever I23 and plate I5, a suitable adjustment screw I29 threaded in plate I5 and locked by nut I30 being provided for factory adjustment.

When tuning shaft I I9 is rotated, tuning lever H3 and yoke I05 are oppositely rocked about their respective pivots and with the aid of springs 29 provides substantially parallel displacement of plates I l and i5 toward each other as in Figures 1-5. During rotation of shaft H9, shaft I25 which is of much finer thread, does not turn relatively to shaft H9 and moves axially with shaft 5 It so that trimmer lever I23 moves parallel with tuning lever I13, and the resultant motion of strut I28 is substantially the same as if levers I I3 and 123 were solid with each other.

Rotation of tuning shaft II9 accomplishes coarse tuning of the device II throughout the full range permitted by the resonator diaphragm. If desired a sensing device similar to that in Figure 2 may be provided here. Fine frequency adjustment is accomplished by rotation of trimmer shaft 25 only to rock lever I23 relative to lever I I3 and thereby cause relative pivotal movement of plates I4 and I5 about studs I06 and I01. Since the amount of such fine adjustment movement is small, the departure from parallelism of the resonator grids is very small and permissible.

In the various embodiments of the invention, rotation of knob II of Figures 1-5, knob 99 of Figures 6-8 and knob I21 of Figures 9 and 10 provides an adjustment of resonator frequency throughout the full range permitted by the flexible diaphragm of the resonator. This is a distinct advantage over prior lever types of tuner mechanisms wherein a lever acted on only one strut to obtain the desired relative displacement between the grids, the remaining two struts acting as pivots similarly to the trimmer action in Figures 9 and 10. Because of the resultant tilting action of the electrodes, the range of tuning in such prior devices was undesirably limited. In the present invention, the available parallel 'motion permits frequency adjustment over the full range permitted by the resonator diaphragm.

The present invention is also more efiicient and advantageous than previously proposed differentially and fine threaded coaxial tuning mechanisms for obtaining parallel motion of the grids since such differential and fine thread devices are subject to excessive wear and thread jamming because of the large forces required for distortion of the diaphragm, and in the present invention the force multiplication obtained by the lever system incident to the motion reduction provided to obtain the necessary small tuning movements aids life and efiiciency of the tuning mechanism.

Since the invention provides full range tuning, the factory adjustment screws, as at 49-5I in Figure 1, at 94-=95 in Figures 6-8 and at I08, 00, 520 in Figures 9 and 10, may be sealed as with wax when the factory setting is complete to prevent unnecessary tampering with this adjustment in the field. The present invention insures optimum progressive and reproductive frequency adjustment of the cavity resonator.

The invention may be embodied in other spacific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A tuning apparatus for a cavity resonator having opposed electron permeable sections interconnected to permit movement toward and away from each other, comprising a pair of spaced members each rigid with one of said opposed sections, a first transverse lever pivoted on one of said members, a second transverse lever pivoted on said one member and operatively connected to said first transverse lever to rock oppositely to pivotal movement of said first transverse lever, longitudinally extending struts rigidly interposed between said levers and said other spaced member, means linked to at least one of said members for resiliently urging said members toward each other, and means for actuating said levers about their pivots to produce parallel movement of said members and consequently of said opposed electron permeable sections toward and away from each other.

2. A tuning apparatus as defined in claim 1, said transverse levers comprising oppositely extending generally semi-circular portions having pivotal bearing contact at their terminals.

3. A tuning apparatus as defined in claim 1, said spaced members each comprising an annular plate, and said plates being substantially parallel with said. transverse levers and struts between them.

4. Tuning mechanism for a cavity resonator having spaced electrodes movable toward and from each other in a certain direction comprising a pair of resiliently biased oppositely rockable levers operatively interposed between said electrodes and pivoted on axes transverse to said direction, and means for simultaneously rocking said levers about their pivots to produce substantially parallel movement of said electrodes toward and away from each other.

5. A tuning mechanism as defined in claim 4, one of said levers having an arm extending substantially in said direction, and said last-named means comprising micrometer adjustment means connected to said arm.

6. Tuning mechanism for an electron discharge device of the type wherein a pair of spaced electron-permeable electrodes adapted to contain a portion of an ultra-high-flrequency field between them are mounted for relative movement toward and from each other, comprising a pair of members each rigid with one of said electrodes and spaced apart a distance appreciably greater than that between said electrodes, a pair of oppositely movable transversely disposed levers mounted on one of said members, a plurality of longitudinally extending struts rigidly interposed between said levers and said other member, means linked to at least one of said members for resiliently urging said members toward each other, and means for actuating said levers about their pivots to produce parallel movement of said members and consequently said electrodes toward and from each other.

'7. A tuning apparatus for high frequency apparatus having a hollow resonator and having a pair of spaced electron permeable wall portions relatively adjustable for movement toward and from each other in a selected direction, comprising means for adjustably controlling the resonator frequency comprising a plurality of separately pivoted oppositely rockable levers and associated struts interconnecting said wall portions, and means for actuating said levers to effect said relative movement.

8. In tuning apparatus for an electron discharge device having a pair of spaced electrodes and a pair of spaced members each rigid with a respective one of said electrodes, the combination comprising a plurality of pivot means on one of said members, a tuning lever rockable on said pivot means, a second lever rockable on the remainder of said pivot means on said one member, means providing a motion transmitting connection between said levers such that movement of said tuning lever in one direction about its pivot means produces opposite rocking movement of said second lever, rigid struts interposed between said levers and said other member, adjustment means for rocking said tuning lever about its pivot means, and resilient means opposing relative displacement of said members.

9. In an electron discharge device having a pair of spaced electrodes adapted for defining an ultra high frequency field portion between them and means for passing an electron beam in energy exchanging relation with said field, the combination with said pair of spaced electrodes com-- prising a pair of spaced members each rigid with one of said electrodes, and means for selectively producing substantially parallel relative movement of said electrodes toward and from each other comprising a pair of oppositely rockable pivoted levers interconnected by a motion transmitting connection and operatively interposed between said members, and manual adjustment means for moving one of said levers.

10. In tuning apparatus for a cavity resonator having spaced electrodes movable toward or from each other in a certain direction, the combination with said spaced electrodes comprising a tuning lever rockable about an axis transverse to said direction, an oppositely rockable transversely disposed second lever operatively interconnected to said tuning lever, and resiliently biased motion transmitting means interposed between said tuning lever and said electrodes for producing substantially parallel movement of said electrodes toward or away from each other upon rocking of said tuning lever.

11. In tuning apparatus for a cavity resonator having spaced electrodes movable toward or away from each other in a certain direction, the combination comprising a tuning lever rockable about an axis transverse to said direction, resiliently biased motion transmitting means interposed between said lever and said electrodes for producing substantially parallel movement of said electrodes toward or away from each other upon rocking of said tuning lever, and cooperating coarse and fine adjustment means for rocking said tunin lever about its pivot.

12. In the tuning apparatus defined in claim 11, said coarse and fine adjustment means comprising differently threaded coaxial shafts having separate operating knobs, the inner trimmer shaft bearing on said tuning lever and having fine threaded support with the outer tuning shaft which has relatively coarse threaded rotatable support in said apparatus.

13. In an electron discharge device wherein a pair of spaced grid or like electrodes are mounted -for movement toward or away from each other in a certain direction, the combination with said pair of spaced electrodes, comprising a. pair of transversely projecting members each rigid with one of said electrodes, a tuning lever pivoted on one of said members in the space therebetween and about an axis transverse to said direction, a yoke also pivoted on said one member, said tuning lever being bifurcated in a transverse portion within said space and having its terminals connected in pivotal bearing engagement with said yoke so that rocking of said tuning lever in one direction produces opposite rocking movement of said yoke, struts rigidly interposed between said lever and yoke and the other of said members, resilient means urging said members toward each other, and means for controllably adjusting said tuning lever about its pivot.

14. A tuning apparatus for an electron discharge device, said device comprising a cavity resonator having a shell with generally parallel end walls provided with aligned grids or like electronpermeable electrodes, one of said shell walls being flexible to permit movement of said electrodes toward or away from each other in a certain direction, said tuning apparatus comprising a pair of annular members one rigid with each of said electrodes, a tuning lever pivoted upon one of said members about an axis transverse to said direction, said lever having a bifurcated transverse portion extending within. the space hetween said members, a yoke pivoted on said one member within said space and having its ends in pivotal bearing engagement with the ends of said transverse portion of said tuning lever, a plurality of struts rigidly interposed between said lever and yoke assembly and said other annular member, and resilient means for urg ng said annular members toward each other.

15. A parallel motion tuning mechanism especially for a cavity resonator having spaced electrodes, comprising a rockable pivoted tuning lever, and a second lever oppositely rockable and pivotally engaging said tuning lever wherein rocking movement of said tuning lever about an axis transverse to the desired direction of displacement of said spaced electrodes of said resonator is converted to parallel movement of said electrodes toward or away from each other.

16. Compound tuning mechanism for a cavity resonator having spaced electrode control members movable toward and from each other in a certain direction comprising a pair of resilientl} biased oppositely rockable levers pivoted on one of said members, a third lever rockably mounted on one of said pair of levers, a plurality of struts interposed between the other of said pair of levers and the other of said members, a strut interposed between said third lever and said other member, means for actuating said pair of relatively rockable levers to obtain substantially parallel relative movement of said electrodes toward or away from each other, and fine adjustment means for rocking said third lever about its pivot.

17. Tuning mechanism for a cavity resonator wherein relative displacement of two spaced electrodes is permitted by a flexible connection between the electrodes comprising a system of resiliently biased levers adjustable for obtaining relative parallel displacement of said electrodes throughout substantially the full range permitted by said flexible connection, and means for controllably adjusting said system, said levers comprising a first pivoted lever, and a second oppositely rockable pivotal lever, said levers being connected at their terminals in a pivotal bearin engagement.

18. In the tuning mechanism defined in claim 17, means for adjusting a part of said system to obtain finer adjustment of the resonator frequency.

19. High-frequency tuning apparatus for a cavity resonator having a pair of spaced walls determining the resonant frequency thereof, comprising a pair of members rigid respectively with said walls, a first lever having a pivot fixed to one of said members, a second lever also having a pivot fixed to said one member, one end of said first lever engaging one end of said second lever, and a plurality of struts extending between said levers and the other said member whereby, upon actuation of one of said levers, force is transmitted simultaneously to all said struts to produce motion of said wall portions in substantially parallel planes.

20. High-frequency tuning apparatus for a cavity resonator having a pair of spaced walls determining the resonant frequency thereof, comprising a pair of members rigid respectively with said walls, a first lever having a pivot fixed to one of said members, a second lever also having a pivot fixed to said one member, one end of said first lever engaging one end of said second lever, and force-transmitting means extending between said levers and the other said member whereby, upon actuation of one of said levers, force is transmitted between said members to produce motion of said wall portions in substantially parallel planes.

21. High-frequency tuning apparatus for a cavity resonator having a pair of spaced walls defining the resonant frequency thereof, comprising a first lever having a pivot fixed with respect to one of said wall portions, a second lever also having a pivot fixed to said one wall portion, one end of said first lever engaging one end of said second lever, and force-transmitting means extending between said levers and the other of said wall portions whereby, upon actuation of one of said levers, force is transmitted to produce relation motion of said wall portions.

LLOYD F. SORG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,311,658 Hansen et a1. Feb. 23, 1943 2,380,946 Cooke et al. Aug. 7, 1945 2,414,785 Harrison et al Jan. 21, 1947 

